1. Field of the Invention
This invention relates to a non-toxic, water-based coating composition which, when applied to the surface of a substrate, particularly leather and vinyl materials, dries rapidly to provide a tough, protective film bonded firmly to the surface. This invention also relates to the method of using this coating composition.
2. Background Discussion
It is desirable to apply protective coatings to a wide variety of materials. For example, vinyl or leather upholstery for furniture and automobiles, articles of clothing like shoes and jackets, and objects such as purses, wallets, etc. all have an enhanced appearance if coated with a liquid which forms a durable film after evaporation of the carrying agent for the film forming material. U.S. Pat. No. 3,597,373 illustrates a typical coating composition which uses hydrocarbon solvents for the film forming material. These solvents are irritating to skin and mucus membranes, or even toxic upon prolonged exposure. Another disadvantage of hydrocarbon solvent based resin coatings is that the film formed tends to be inflexible. To overcome this, plasticizers are blended in the coating. These plasticizers migrate from the film over a period of time and may leave on the surface of the film a sticky, oily residue. Expensive blocking agents are used to inhibit the migration of the plasticizers from the film's surface. Eventually, the film becomes brittle when the plasticizers have volatized or have been transferred due to contact with other substrates and are no longer present in a sufficient amount to maintain the desired flexibility. Antioxidants are used in hydrocarbon solvent based resin coatings to speed drying and prevent decomposition of the film by air oxidation. Stabilizers are also used in hydrocarbon solvent based resin coatings to impart ultraviolet light resistance to both the coating and the resulting film. These are expensive and sometimes toxic ingredients.